The \(T\) -dependence observed in unsuspended graphene is considerably different. There, \(\rho (T)\)  is approximately linear for \(T\le 100\)  K, while it is superlinear for \(T>100\)  K [1]}, [2]}. The lack of such activated behavior in our suspended devices shows that such activated behavior is not an intrinsic property of graphene, but rather stems from the external sources, such as remote interface phonons [2]} or static ripples [1]}. In fact, suspended graphene shows only a modest increase of the resistivity from \(T\sim \) 5 K to 240 K maintaining a mobility of \(\mu =120,000\)  cm\(^2\) /Vs at T=240 K and at our highest density of \(n=2 \times 10^{11}\)  cm\(^{-2}\) . This value considerably exceeds the highest reported room-temperature mobility for a semiconducting material (InSb, 77,000 cm\(^2\) /Vs [5]}).
